<template>
  <div class="todo-container">
    <div class="todo-wrap">
      <Header 
      :addItem="addItem"
      :todoList="todoList"></Header>
      <List 
      :todoList="todoList" 
      :changeItemDone="changeItemDone"
      :deleteOne="deleteOne"/>
      <Footer 
      :todoList="todoList"
      :checkAll="checkAll"
      :deleteSomeItem="deleteSomeItem"></Footer>
    </div>
  </div>
</template>

<script>
import Header from "@/components/Header";
import Footer from "@/components/Footer";
import List from "@/components/List";
export default {
  name: "App",
  components: {
    Header,
    Footer,
    List,
  },
  data() {
    return {
      todoList: [
        { id: "001", done: false, content: "吃饭" },
        { id: "002", done: false, content: "睡觉" },
        { id: "003", done: false, content: "打豆豆" },           
      ],
    };
  },
  methods: {
    //增加item
    addItem(newItem) {
      this.todoList.unshift(newItem)
    },
    //选中或不选中，要改变done的值
    changeItemDone(id) {
      this.todoList = this.todoList.map(item => {
        // console.log(item,'======')
        if(item.id === id) item.done = !item.done;
        return item;
      })
      // console.log(this.todoList,'---====----');
    },
    //全选
    checkAll(newDone) {
      this.todoList = this.todoList.map(item => {
        item.done = newDone;
        return item;//要记得return item ,而不是 返回item.done = newDone，那就得到的是 =号右边的值了;
      })
    },
    //删除单个item
    deleteOne(id) {
      this.todoList = this.todoList.filter(item => item.id !== id); 
    },
    //批量删除item
    deleteSomeItem() {
      this.todoList = this.todoList.filter(item => !item.done); 
    }
  },
  mounted() {
    //初始化
    this.todoList = JSON.parse(localStorage.getItem('todoList') || "[]");//因为在数据注入后，mounted由对todoList做了初始化，所以localstorage中无数据的时候，会走|| 后面的 ‘[]’
  },
  watch: {//监听数据的改变，存储
    todoList: {
      // immediate: true,不可以设置立即监听，否则每次刷新，都会重新立即获取一份，原来data中的数据，存储起来，之前localStorage存储的数据被覆盖
      deep: true,
      handler(){
        localStorage.setItem('todoList',JSON.stringify(this.todoList));
      }

    }
  }
};
</script>

<style>
/*base*/
body {
  background: #fff;
}

.btn {
  display: inline-block;
  padding: 4px 12px;
  margin-bottom: 0;
  font-size: 14px;
  line-height: 20px;
  text-align: center;
  vertical-align: middle;
  cursor: pointer;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.2),
    0 1px 2px rgba(0, 0, 0, 0.05);
  border-radius: 4px;
}

.btn-danger {
  color: #fff;
  background-color: #da4f49;
  border: 1px solid #bd362f;
}

.btn-danger:hover {
  color: #fff;
  background-color: #bd362f;
}

.btn:focus {
  outline: none;
}

.todo-container {
  width: 600px;
  margin: 0 auto;
}
.todo-container .todo-wrap {
  padding: 10px;
  border: 1px solid #ddd;
  border-radius: 5px;
}
</style>
